Improvement in geates foe hot-aie fuenaces



E. S. RENWICK.

Furnace Grate.

Patented Aug. 18, 1868.

N. PETERS PhMo'LMwgx-aphw. Washington. D. C.

EDWARD SABINE RENWICK, OF NEW YORK, N. Y.

Letters Patent No. 81,109, dated August 1s, 1868.

IMPROVEMENT IN- GRATES' FOR HOT-AIR FURNACES.

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Be it known that I, EDWARD SABINE RENivIcK, of the city, county, andState of New York, have invented certain new and useful Improvements inGrates for Hot-Air Furnaces, and for other furnaces to which saidimprovements may be applicable; and that the following is a full, clear,and exact description and specification of my invention.

Great difliculty has been experienced by housekeepers in having theirfurnace-grates cleared of ashes, the diflicnlty arising from, the wantof eficient means by which women-servants can do the work. A similardifliculty has been experienced in clearing the grates of the furnacesof steam-boilers of ashes and clinker, and

.for the want of efficient means for that purpose; p

The object of my invention is to provide such means; and it consists,first, of the combination of the following instrumentalities, viz, thefire-box of the furnace; two gangs of grate-bars, the members of whichare arranged alternately in the grate, and one of which gangs isrcciprocatable longitudinally relatively to those of the other; arock-shaft or journals, with which the grate-bars are connected, so thatthey may be tipped or turned out of their horizontal positions, todischarge the contents of the fire-box; and'agrate-bar mover, conncctedwith the reciprocatable grate-bars, by a connection applied to them inthe vicinity of the axis of said rock-shaft or journals, so that thememhersof one gang of grate-bars may he moved longitudinally withoutmoving those of the other gang simultaneously in the same direction, andalso that the grate-bar mover need not be disconnected, either from itssupportsor from the grate-bars when the grate is tipped, or is restoredto its place.

My invention consists, further, of the combination of the fire-box, twogangs ofgrate-bars, rock-shaft, and grate-bar mover, ,as abovespecified, witha lever-handle arranged at the exterior of the ash-pit,so that the 'furnace eontents may be readily discharged, and that thereciprocatable gang of grate-bars may be moved longitudinally, while theash-pit is closed by a door, so as to prevent the escape of ashes.

My said improvements may be embodied in various forms, "and in orderthat my invention'may be understood, I have represented in theaccompanying drawings several of the-modes in which I have contemplatedthe application of the principle or characteristic by which my inventionmay be distinguished from others-- Figure 1 representing a front view ofthe front plate and appurtenancesof a hot-air furnace, embodying myimprovements, Figure 2 representing a side view of portions of saidfurnace,

Figure 3 representing a vertical section of the same,'and

Figure 4 representing a plan of thefurnace, with certain parts removed,to permit the grate-bars and their "appurtenances to be seen.

Figures 5 and 6 represent respectively a vertical section and plan ofanother hot-air furnace, with a difl'erout form of grate andappurtenances, and I i Figure 7 represents a grate-bar,-with one of theforms of the surface projections which I employ.

The form of fire-box with which the remaining members of mycombin'ati'onsare combined, is not material to the invention. In thefurnace, parts of which are represented in figs. 1 to 4, the firebox Ais quadrangular, and it is supported, in the usual manner customary inhot-air furnaces, upon an iron ash-pit, B, having a hole in its topcorresponding with the opening in the bottom of the fire-box; Thegrate-bars of this furnace are divided into two gangs, the members a a aof one of whichnre, for distinction, colored blue in figs.'3 and 4,while the members e e e of the other gang are colored red. The members aa a of one gang are all secured to a rock-shaft, m, which crosses theash-pit, and has journals at its ends, which are fitted to turn in holesmade in the opposite sides of the ash-pit, so that said sides formbearings for the rock-shaft to turn upon. The members e e e of theother'gnng of grate-bars alternate with those of the first, and arereciproeatable longitudinally I relatively to them, as they are arrangedto slide longitudinally. upon cross-bars it 12, secured to the firstgang;

and said cross-bars have slight depressions in them, corresponding withthe reciprocatable bars, so as to guide the latter in their longitudinalmovement. All the reciprocatablc bars in this example are connected witha cross-bar, 8, whose ends project beyond the grate-bars, and are formedinto journals, which are connected by rods t t with two arms, 6 b,projecting downwards from an operating-shaft, d; that is supported inbearings secured to the front plate 0 of the furnace. In passing to thisoperating-shaft, the rods t t pass through holes made in the front plateI} for the purpose. The operating-shaft dis providedwith alever-handle,f, which, for convenience, is fitted in a sock-ct formedin-one of the arms 6. In order that the grate may he held in itshorizontal position, a sliding ho'lde'r, is provided, to engage with theprolonged ends o 0 of two of the grate-bars; and as the remaininggrate-bars are connected with these two by the"cross=bars n n, the wholegrate is held from tipping or turning out of its horizontal position.The upper surfaces of the grate-bars are indented, so as to produceprojections, as represented in fig. 3.

When theashes are to be discharged-from the fire-bait of'the furnaceabove described, the operating-shaft d, with its arms 6 b, whichconstitute the grate-bar mover, is rocked to and fro by applying thehand to the lever-handle), and the gang of reciprocatable grate-bars e ca is thereby caused to reciprocate longitudinally relatively to themembers of the other gang, a a a; As the coals in the fire-box rest inpart upon the reciprocatable grate-bars, and in part upon the residue,the coals will be acted upon by two forces, one of which tends to keepthem from moving with the reciprocatable bars, and the practical resultis that the coals are caused to grind upon. each other, and the ashesare effectually expelled. Moreover, as the lever-handlefis at theexterior of the ash-pit, and as the rods t t (which connect that handlewith the reciprocatable gang of grate-bars within,) extend through smallholes, the ash-pit maybe closed by a door,-w, arid the ashes and dustare practically retained in the ash-pit, and prevented from annoying theoperator during the raking of the fire. The projec tions on the uppersurfaces of the grate-hars enable th'e latter to take a better hold ofthe coals and facilitate the operation. When the contents of thefire-box are to be discharged, the holder 9 is pulled forward, so as todisengage it from the grate-bars, and permit the whole grate to tip orturn downwards upon the rock-shaft m, as an axis, and as the connectionof the rods t t with the reciprocatable grate-bars is applied to thelatter, close to the axialline of the rock-shaft m, the turning of thegrate either up or down does not practically affect the connection withthe operating-shaft cl and lever-handle f. l

In the furnace, parts of which are represented in figs. 5 and 6, thefirebox A is circular, and the grate is arranged to turn upon one of itsdiametrical lines as an axis. In this example, the gang of thereciprocatable grate-bars, c e e, are all connected by a centralcross-bar, s, and the central grate-bar is extended, to form theconnection it with the.gratebar mover b, by which the whole gang iscaused to move longitudinally. The other gang of grate-bars, a a a, areconnected together by cross-barsn n. This gang is fitted at its rearside with a I journal, m, that is supported in a bearing, 1, at the rearof the grate, and at the front side with a tubularjournal, m, that issupported in a bearing, 11:", at the front side of the grate, so thatthe gang can be tipped or turned upon said journals; and as the gang ofrcciprocatable bars is connected with the other gang by the cross-bars ns n, the entire grate can be turned on the journals m m, out of itshorizontal position, for the purpose of discharging the contents of thefirebox. In order that the reciprocatable bars of this form of grate maybe moved longitudinally withlease, they are connected by the connection15 with an arm, b, which forms the grate-bar mover, and projectsdownwards from an operating-shaft, d, at the front of the furnace, andaleverhandle, f, is provided, for the purpose of rocking said shaft. Thearm bis forked, so as to embrace the connectingbar or connection'lt, andthe latter is fitted with collars, z 2, which compel it to move to'andfro with the arm 5, and at the same time do not prevent it from turningon itsaxis. In order that the grate may be readily tipped or turned, theend of the connection t is fitted with a crank-handle, 7t, and as thesaidconnection is connected with all the grate-bars through thecross-bars n s n, the turning of it compels the whole grate to turn. Thelever-armfmay be arranged either directly over the connectioii t, or atone end of the operating-shaft d, at the'sido of the door of thefurnace, as found eirpedicnt. I j

In both the above examples the arm or arms 6 b', constituting thegrate-bar mover, are connected with the reciprocatable gangof grate-barsby a connection (consisting of rods or a bar,) which is applied to thatgang in the vicinity of the rock-shaft or journals on which the grate isconstructed to tip; hence the grate-bar mover is not disconnected,either from its supports, or from the grate when the latter is tipped todischarge the contents of the fire-box, and consequently neither timenor care is required to restore the' grate-bar mover to its positionwhen the grate is replaced in its horizontal position.

In some cases I prefer to form th'e projections upon theupper' surfacesof the grate-bars, as represented in fig. T, or saw-toothed. The effectof this form of projection is to work the clinker progressivelyforwards, so as to discharge it at the front ends of the grate-bars, andin this case an opening should be left between the front of the grateandthe front side of the firc-box above it, for the. escape oftho'clinkers.

In place of arranging the operating-shaft (Z of the furnace, representedin figs. to 4, to rock, it may be arranged to turn in its bearings, andit may be fitted, in placeof arms, with eccentrics, the rings of whichare connected with the rods 15 t, so that by turning said shaft thereciprocating longitudinal movement may be imported to the grate-bars.This construction is advantageous for steam-boiler furnaces orfire-bores, as a rotary motion can, in such .cas es, be readily impartedto the shaft,fr0m the steam-engine. In some cases I intend to make bothgangs of grate-bars reciprocatable longitudinally at the same time, butin opposite directions, the effect of which upon the coals" will be thesame as making the members of one gang reciprocate longitudinally, andthose of the other gang stationary, but in such cases the length ofmovement need'be only half as much to produce the same effect. I

Having thus described the-several modes in which I have contemplated theapplicationof the principle of my invention, I declare that I do notclaim the several instruincntalities of which my combinations arecomposed, separately from the combinations; but

What'I claim as my invention, and desire to secure by Letters Patent, is

The combination of the following insti-nmentalities, viz, the fire-box,two gangs of grate-bars, the members of one of which a're reciprocatablelongitudinally relatively to those of the other, a rook-shaft, withwhich the grate-bars are connected, so that they may be tipped, and agrate-bar mover, connected with one gang of grateba'rs in the vicinityof the axis of the rock-shaft, all operating substantially as before setforth.

Also the combination of the following instrumentalities, viz, thefire-box, two gangs of grate-bars, having the relationship afox esaid,the rock-shaft, on which the grate may be tipped, the grate-bar mover,connected with one gang of grate-bars in the vicinity of the axis of therock-shaffland a lever-handle, arranged at the exterior of the ash-pit,substantially as before set forth.

In testimony whereof, I have hereto set my hand, this first day ofFebruary, A. D.-1868.

' EDWARD SABINE REN WICK.

Witnesses:

J. RATHBONE, Jr., W. L. BENNEM.

